Convert CONFIG_FSL_MEMAC et al to Kconfig

This converts the following to Kconfig:
   CONFIG_FSL_MEMAC
   CONFIG_SYS_MEMAC_LITTLE_ENDIAN

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/ls2081ardb_defconfig b/configs/ls2081ardb_defconfig
index fb7faa4..e6e6fe6 100644
--- a/configs/ls2081ardb_defconfig
+++ b/configs/ls2081ardb_defconfig
@@ -72,6 +72,8 @@
 CONFIG_PHY_AQUANTIA=y
 CONFIG_PHY_CORTINA=y
 CONFIG_CORTINA_FW_ADDR=0x980000
+CONFIG_FSL_MEMAC=y
+CONFIG_SYS_MEMAC_LITTLE_ENDIAN=y
 CONFIG_E1000=y
 CONFIG_MII=y
 CONFIG_NVME_PCI=y